IBA Porlier Pass
Valdes & Galiano Islands, British Columbia
Site Summary
BC052 Latitude
49.012° N
123.591° W
0 m
15.58 km²
open sea
Land Use:
Potential or ongoing Threats:
Disturbance, Oil slicks
IBA Criteria: Globally Significant: Congregatory Species, Continentally Significant: Congregatory Species
Conservation status: IBA Conservation Plan written/being written
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Site Description
Porlier Pass is the channel between the southern end of Valdes Island and the northern end of Galiano Island within the southern Gulf Islands in the Strait of Georgia. It lies about 17 kilometres east of the town of Ladysmith on Vancouver Island, British Columbia. The pass is a tidally active body of water about two kilometres long and less than one kilometre wide. Strong tides run through the pass each day as the waters flood and ebb between the Strait of Georgia to the east and Trincomali Channel and others to the west. As with Active Pass to the south and Gabriola Pass to the north, Porlier Pass is a site of strong topographic upwelling, caused by deep waters being brought to the surface in the narrow, shallow passage. The boundaries of the site encompass the waters of the pass in a 1.5 kilometre radius and extend along the northern shoreline of Galiano Island from Alcala Point to Dionisio Point, and from Shah Point to Cardale Point on the southern shoreline of Valdes Island.
Although bird use of Porlier Pass is not as well known as that of Active Pass to the south, the proximity and similar characteristics of the two sites leads to comparable assemblages of marine birds. Tidally active channels typically attract fish-eating birds. Periodic surveys in the region (in the 1970s and 1990s) have recorded a wide variety of marine birds in the pass, particularly in winter months. In November 1971, 1,000 Mew Gulls were tallied; this represents approximately 2% of this holarctic species North American population. In January 1993, 3,010 cormorants were recorded, consisting of three species: Brandt's, Double-crested and Pelagic. A flock of this size means that each species probably reached at least national significance levels but, without a breakdown of species composition, this is not known. Considering that large numbers of Brandt's Cormorant winter in the southern Gulf Islands, it is likely that a majority of this flock consisted of this species. If so, this would meet global level IBA criteria.

In general, a wide variety of marine birds use the pass, especially in winter months. These include waterfowl, loons, grebes, gulls and alcids. Canoe Islet, an Ecological Reserve just north of Porlier Pass along the east coastline of Valdes Island, has a small colony of breeding Glaucous-winged Gulls and Black Oystercatchers.

IBA Criteria
SpeciesT | A | I Links Date Season Number G C N
Note: species shown in bold indicate that the maximum number exceeds at least one of the IBA thresholds (sub-regional, regional or global). The site may still not qualify for that level of IBA if the maximum number reflects an exceptional or historical occurrence.
Conservation Issues
No conservation measures have been taken to date. The main potential threats are oil spills and discharges from ships in the area, and disturbance of the birds from recreational boaters.

The IBA Program is an international conservation initiative coordinated by BirdLife International. The Canadian co-partners for the IBA Program are Birds Canada and Nature Canada.
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